Prior and existing remote measurement devices for remotely monitoring the concentration of a particular gas species in a gaseous mixture are based on techniques involving laser-induced Raman and fluorescent scattering, correlation spectrometers, and interferometers which techniques have serious drawbacks.
Data obtained using laser techniques is difficult to interpret due to interfering species and the intervening atmosphere.
The correlation spectrometer and interferometer, while quite specific, are unfortunately very dependent upon the temperature of the source effluent.
None of the existing methods, save for that of the instant invention, are thus satisfactory when it comes to, for example, measuring gaseus pollutants emitted from stationary sources such as smokestacks, which may be at a distance exceeding one kilometer.